A Buffer Solution with a PH of 4

Multiple Choice

A buffer solution with a pH of 4.63 is prepared with 0.14 M formic acid and ________ M sodium formate. The K_a of formic acid is 1.8 × 10^-4.

A) 1.1
B) 2.1
C) 5.4 × 10^-6
D) 3.0 × 10^-8
E) 0.54